NFS transfer times

Hi Folks,

Heres the situation. 2 DS10s (1 Server 1 Statation) running VMS 7-3-2 TCPIP 5-4 ECO 5. The DS10 AlphaStation is configured as the NFS server, the other DS10 is the client. During a test the client was able to transfer data from the server at a rate of 5 Mbytes per second, however transferring data to the server went at 0.9 Mbytes per second. At the time of the test there was no other LAN or disk activity.

The network i/f is at 100Mbs and both sides have autonegotiated to a 100 full. I suppose the questions are:

1) Is this normal?2) If this behaviour is not normal what on the server could cause this discrepancie?

I'm tied to using NFS in this situation, the customer is adamant that we cripple our systems with unix stuff.

Re: NFS transfer times

Brian,

consider to test the same or similar file transfer with FTP to see, if you achieve, better, worse or about the same performance. This could then point you in the direction to where the problem may be...

Re: NFS transfer times

Hi Brian,

I suspect that the NFS client has duplex incorrectly negotiated.

If you are running with the latest LAN patch for V7.3-2, you can use mc lancp sho dev /int to see if the duplex is OK.

Otherwise check the counters using lancp show dev/count, if there are increasing errors like alignment errors, frame check errors or receive data length errors, the there is some problem with duplex between controller and switch port.

Re: NFS transfer times

Hi Folks

Sorry about the delay getting back. Had time off to cover staff development days at the school :)

Anyway, barring a single CRC error there was nothing untoward in the MC LANCP SHO DEV/COUNTERS, SHO DEV/CHAR indicates full duplex at a 100 MB. This interface gets used a lot by the applications and normally a mismatched duplex results in the system not working too well.

I repeated the file transfer test using FTP on the interface, FTP is around 4 to 5 times faster in both directions. Although writing files back on the server unit seems slightly slower (3 Mbytes a second vs 4 Mbytes for the client writing the file), but still substantially faster than the observed NFS performance.

So it could be some issue with the disks on the Server. I'll do some more tests when I get through the pile of post-holiday paperwork :)

Re: NFS transfer times

Sorry should have been clearer with the FTP statements. FTP copying stuff from the client to the server (get from server and put from the client) are running at the speeds I'd expect (between 3 and 4 Mbytes).

Re: NFS transfer times

Well after a PC upgrade at work which lost various bits of email and cookies, I can now at least provide some more information.

mc lancp sho dev/intIndicates both sides of the network are at 100MB FULL.

There is nothing odd in the counters from LANCP (that I can see anyway).

From TCPIP SHO NFS, the NULLRECV count is high. Calls = 35099, Nullrecv = 27540. According to the unix docs I've seen all this means is that the NFS Server is not nusy enough (too many threads I'd guess).

FWIW the switch is unmanaged and shows as 100 Mb FULL.

The target disk is ODS-5 with highwater marking disabled.

I've attached a text file with the results from MONI IO, FCP and LOCK averaged out over a couple of runs of the copy procedure. I aplogise in advance for it being a non-VMS file.

Anything else I should be looking at? Or more to the point have I forgotten something obvious :)